fix many compilation warnings about static variables used by non-static functions

[CC] plc_main.c -> plc_main.o
/tmp/be/build/plc_main.c:396:40: warning: ?LogBuff? is static but used in inline function ?copy_from_log? which is not static
memcpy((char*)buf + remaining, LogBuff[level], size - remaining);
^
/tmp/be/build/plc_main.c:395:22: warning: ?LogBuff? is static but used in inline function ?copy_from_log? which is not static
memcpy(buf, &LogBuff[level][buffpos], remaining);
^
...

^
/tmp/be/build/plc_debugger.c:825:20: warning: ?retain_offset? is static but used in inline function ?BufferIterator? which is not static
Retain(retain_offset, size, real_value_p);
^
/tmp/be/build/plc_debugger.c:823:47: warning: ?retain_offset? is static but used in inline function ?BufferIterator? which is not static
unsigned int next_retain_offset = retain_offset + size;
^
^

"""
Misc definitions
"""

import os,sys

# helper func to check path write permission
def CheckPathPerm(path):
    if path is None or not os.path.isdir(path):
        return False
    for root, dirs, files in os.walk(path):
         for name in files:
             if os.access(root, os.W_OK) is not True or os.access(os.path.join(root, name), os.W_OK) is not True:
                 return False
    return True

def GetClassImporter(classpath):
    if type(classpath)==str:
        def fac():
            mod=__import__(classpath.rsplit('.',1)[0])
            return reduce(getattr, classpath.split('.')[1:], mod)
        return fac
    else:
        return classpath

def InstallLocalRessources(CWD):
    from BitmapLibrary import AddBitmapFolder
    from TranslationCatalogs import AddCatalog
    import wx

    # Beremiz bitmaps
    AddBitmapFolder(os.path.join(CWD, "images"))

    # Internationalization
    AddCatalog(os.path.join(CWD, "locale"))
    import gettext
    import __builtin__
    
    __builtin__.__dict__['_'] = wx.GetTranslation